Reproducing magnet for telegraphones



Oct. 20, 1931. c. STILLE ,2

REPRODUCING MAGNET FOR TELEGRAPHONES Filed April 12, 1929 /n ven tor J+,'//e

Patented Oct. 20, 1931 UNITED STATES PATENT OFFICE CUR'I' STILLE, OF BERLIN, GERMANY, ASSIGNOR TO TELEGRAPHIE-PATENT-SYNDIKAT G. M. B. H., OF BERLIN, GERMANY REPRODUCING MAGNET FOR TELEGRAPHONES Application filed April 12, 1929, Serial No. 354,684, and in Germany September 26, 1928.

It is known that sound records can be electromagnetically fixed on a steel wire and be reproduced. For this purpose, use is made of small magnets which are conveniently assembled in a small casing in such a manner that the fine steel wire can pass through the said casing, entering through a narrow slot, passing along the magnet cores and then leaving the casing again through a narrow slot. This device may be referred to as a talking head. These talking heads are so constructed that all the passages are kept very narrow in order to permit a passage of the wire free of any vibrations. If the wire had for instance a thickened part it could not pass through the said talking heads. wires have recently been successfully used as a musical accompaniment for moving pictures and generally employed as the acoustic part of the so-called talking film. If such a wire is used ina talking film it must be possible to cut it up in exactly the same way as the pictorial part of a film, so that if the pictorial part contains damaged parts which have to be cut off, the corresponding parts of the sound record wire may also be cut off in order that the picture and the sound may be synchronized. However, this would not be possible with the talking heads as now used, since the thickened part at the ends of the wire which are produced by the riveting or welding together of the wire ends could not pass through the normal talking head.

The object of the present invention is to produce a talking head which will allow such thickened wire produced by riveting or welding to pass through.

The inlet-end of the talking'head is funnelshaped and is closed by two movable jaws. When the riveted or welded portion of the wire passes along the said jaws, the latter yield, and by means of a small lever arrangement allow the small magnets of the talking head to return quickly into their position. Movable jaws are also arranged at the outlet end of the wire, which movable jaws release a locking device, thereby eifecting a rapid return of the small electro-magnets intotheir normal position.

Obviously other forms of construction may Now, such record be employed which will produce the same effect, that is to say, that the two halves of the talking head will as a whole recede when the thickened part of the wire passes through, The essence of this invention consists in this, that a talking head is employed which allows thickened portions of the wire to pass through without any disturbance in the operation, which has not been possible with the talking heads as hitherto employed.

- One form of carrying the invention into efiect is illustrated by way of example in the accompanying drawings, in which,

Figure 1 illustrates a horizontal section of the talking head when the wire passes through it, Figure 2 showing the same in elevation, when a thickened portion of the wire passes through.

Figure 3 is an end view of the talking head corresponding to the position shown in Figure 1, whilst Figure 4 illustrates an end view corresponding to the position shown in Figure 2.

The wire 2 with the thickened points 1 passes through a two-partcasing formed by two plates, 3 and 4, and containing the magnets 5 and 6 for the magnetization of the wire. The guiding of the wire is efi'ected along corresponding grooved guiding members 7 and 8, which are constituted by discs provided with recesses 9 "and 10, the journals 7, 7", 8, 8" of the discs being formed with screw threads running in opposite directions. The said screw threaded journals engage in corresponding screw threaded counterparts formed in the plates 3 and 4. Vhen the discs 7 and 8 are rotated in opposite directions, the plates 3 and 4 must either approach or recede from one another. The

discs 7 and 8 are coupled together to rotate in opposite directions, this being effected by means of toothed segments 11 and 12 which are mounted on the screw threaded journals 7 and 8 respectively. If a thickened part 1 of the wire runs towards the left over the disc 7 it strikes against the edge of the recess 9 and consequently turns the disc 7 in such a direction that the plates 3 and 4 of the talking head are moved away from one another. This causes the disc 8 to be rotated in a symmetrical position (see Figure 4), by the cou ling through the segments 11 and 12.

vghen the thickened part 1 reaches the recess 10 in the disc 8, which is now in the po- 5 sition shown in Figure 4, the disc 8 is rotated in the opposite direction and causes the disc 7 to be rotated in a backward direction so that now the plates 3 and 4 together with the magnets are moved back and the distance be- 10 tween the said plates is again normal.

I claim:

1. A reproducing magnet or talking head for telegraphones, capable of allowing the passage of riveted or welded thickened parts of wire, comprising movable jaws carrying the magnets of the telegraphone and having a funnel-shaped inlet end, in combination withmeans provided at the inlet and outlet end of the talking head for respectively positively opening and closing the said aws under the control of the said thickened parts of wire.

2. A reproducing magnet or talking head for telegraphones capable of allowing the passage of riveted or welded thickened parts of wire comprising movable jaws carrying the magnets of the telegraphone and having a funnel-shaped inlet end, in combination with means for respectively positively opening and closing the said jaws under the control of the said thickened parts of wire, the said means comprising grooved guiding discs having recesses, screw-threaded journals mounted with the screw-threads running in opposite directions in the movable jaws on which the said guiding discs are mounted, and toothed segments secured to the screw-threaded journals and in toothed engagement with one another, as set forth.

In testimony whereof I have signed my name to this specification. a

CURT STILLE. 

